/*
 * Copyright 2010 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package java.util;

public class StringTokenizer {
  private final String deli;
  private final String s;
  private final int len;

  private int pos;
  private String next;

  public StringTokenizer(String s, String deli) {
    this.s = s;
    this.deli = deli;
    len = s.length();
  }

  public StringTokenizer(String s) {
    this(s, " \t\n\r\f");
  }

  public String nextToken() {
    if (!hasMoreTokens()) {
      throw new NoSuchElementException();
    }
    String result = next;
    next = null;
    return result;
  }

  public boolean hasMoreTokens() {
    if (next != null) {
      return true;
    }
    // skip leading delimiters
    while (pos < len && deli.indexOf(s.charAt(pos)) != -1) {
      pos++;
    }

    if (pos >= len) {
      return false;
    }

    int p0 = pos++;
    while (pos < len && deli.indexOf(s.charAt(pos)) == -1) {
      pos++;
    }

    next = s.substring(p0, pos++);
    return true;
  }
}
